[AprilB]

OK...I'm developing a beef marinade that I also want to cook down to use as a glaze.

It suddenly dawned on me: Why is the initial marinade thrown out?

Does anyone have the scientifics on exactly why?

I mean, wouldn't it stand to reason that if the marinade was 'contaminated' to the point you couldn't kill the germs when cooking it that it would be the same for the item you're marinating?

I would think that bringing it to a slow boil and then simmering at almost boiling point would kill anything that would be an issue?

Just curious.

April

[Blueicus]

After cooking something, the only danger that remains (apart from high temperature resistance bacteria and virii) are toxins that are made by the bacteria while they were reproducing in the meat/liquid in question. Since the toxins remain in the food long after the bacteria are killed, you can give yourself a pretty bad case of food poisoning if the item in question wasn't dealt with in a proper manner (such as not storing in the danger zone for a long time, etc.) I believe I did that to myself once with oxtail that I had cooked until there was no possible way bacteria could've remained, but I managed to put myself into a bedridden state for three days.

[castironchef]

It is a normal practice to bring marinades to a boil (to kill any microorganisms) and then reduce (to develop and intensify flavor) to make a sauce or glaze.

It's true that any toxins created by those microorganisms would still exist, but that also would be true with the meat you are cooking. Hence, the need to keep the food at food-safe temperatures during the marination process.

[Jayme]

Aside from what has already been mentioned, I have found that the blood and juices from the meat can often "ruin" the marinade. Once cooked, the blood coagulates and changes the consistancy of the marinade- not the beautiful glaze you planned. Best is to mix marinade, reserve some, and put meat in the rest.

[oldschool1982]

I've found that you shouldn't have a great deal of the marinade left over to think about reducing into a glaze. The thought is that no matter how much you use in the container or bag you put the products into, the item you are marinating is going to only absorb so much. There's no sense to use a gallon when a cup would suffice. I have always made marinades in bulk and portioned them for the appropraite size use. Jayme is spot on about everything including the saving some and using it for the glaze.

As far as the bacterium and it's toxins are concerned..... Aren't most marinades acidic by nature? I have always believed because of the acidity it helped to curtail any or almost all rapid bacterial growth. It's also been my belief that it doesn't usually go bad unless it sits around in the cooler/refrig for weeks after use or until you have introduced so much of the meats natural juices (blood from using the marinade too many times) that the marinade looses it's acidic properties and then can become a breeding ground for this bacterium. If toxins were going to be present wouldn't the initial use be affected and then wouldn't that affect the safety of the meat in it. Hopefully before anything could happen that makes the food unsafe, the user would realize the marinade was useless and already discarded it. The "3 strikes theory" or a week SL in total works well for this.

So IMHPO use less marinade in the process and reserve more of the unused for reducing

[Panonthefire]

Originally Posted by Jayme

Aside from what has already been mentioned, I have found that the blood and juices from the meat can often "ruin" the marinade. Once cooked, the blood coagulates and changes the consistancy of the marinade- not the beautiful glaze you planned. Best is to mix marinade, reserve some, and put meat in the rest.

I agree with you, the "osmose" that ocure when you marinate a meat, takes the blood out of the meat.

That makes a bad liquid to reduce.

[KYHeirloomer]

One is the quality of the glaze, the other is the safety.

As to quality, any previously used marinade makes a poor reduction for the reasons already given. It's better to discard it, and use fresh (or reserved) marinade to create sauces and glazes.

Safety is another issue altogether. According to CDC, you can destroy virtually all bacterial toxins at sustained temps of 180 degrees. And USDA says you destroy food borne bacteria by boiling for ten minutes. Thus, taking a used marinade and reducing it should be perfectly safe from a health point of view. But it's likely to taste like crap.